[Nottingham] A numerical puzzle & "mathomatic"

Martin martin at ml1.co.uk
Mon Jan 18 19:54:31 UTC 2010

Richard Ward wrote:
> Rory Holland wrote:
>> I'm using BC to convert between bases for massive numbers
>> See here http://ubuntuforums.org/showthread.php?t=1383101


bc - An arbitrary precision calculator language - The  most  basic
element in bc is the number.  Numbers are arbitrary precision numbers.
This precision is both in the integer part and the fractional part.

and not to be confused with:


dc - an arbitrary precision calculator - a reverse-polish desk
calculator which supports unlimited precision arithmetic.

You can choose to be forwards or backwards! ;-)

I'm still not sure which I prefer. The reverse-polish notation is
natural for programmers that have done a lot of stack-based programming.
Then again, bc is rather good and easy. The arbitrary precision is fun.

> You mention at the beginning of the thread that you don't have 
> Mathematica. It probably won't make that particular calculation go any 
> faster, but if you need a free CAS have you tried wxmaxima? its not as 
> good as Mathematica/Maple, but its alright.

Not seen that one. Will have a look.

I accidentally stumbled across "Mathomatic". It is beautiful for it's
algebra manipulation, even on the command line. Its html output is

> PS. Do you have an answer you are happy with yet?

Yes thanks. Camilo gave likely the best answer by using observation,
deduction and trivial guesses.

The only other ways I can see are to use brute force or to look for the
zero crossing point of the 3d graph of a, b, c (which in a way is a
brute force inspection!).

I was hoping to be purist and do something clever with the algebra that
computed the answer rather than looking for a graph zero crossing...

(Unfortunately, not got much time spare for puzzles... :-( )


Martin Lomas
martin at ml1.co.uk

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